Heretofore, there are nitride semiconductor light emitting devices which include a nitride semiconductor laminated body provided on an opaque and conductive support substrate with a metal reflection film interposed therebetween. In the nitride semiconductor light-emitting device, light is extracted from the nitride semiconductor laminated body side and a path of electric current is formed from the nitride semiconductor laminated body to the support substrate.
The nitride semiconductor light-emitting device is manufactured in the following manner. The nitride semiconductor laminated body is firstly formed on a substrate for growth. A support substrate is bonded to the substrate for growth with the metal reflection film interposed therebetween. Finally the substrate for growth is removed.
In a case where the substrate for growth is a sapphire substrate, when the sapphire substrate is removed through a laser liftoff process, a problem arises in that cracks are generated in a peripheral portion of the nitride semiconductor laminated body due to thermal strain. When a laser beam having a spot diameter as small so as not to cause cracks is used, the occurrence of the cracks can be suppressed. However, the problem with the technique is that time required for the work increases.
In a case where the substrate for growth is a silicon substrate, it is easy to remove the silicon substrate using a wet etching process. However, the exposed surfaces (including the back surfaces and the side surfaces) of the substrate for growth and the support substrate which are bonded each other are inevitably exposed to an etchant.
For this reason, it is required for a portion of the body other than the substrate for growth to be coated with a protective film so that the portion may not be etched. However, the problem with the method is that the etchant soaks a gap between the portion and the protective film, so that the support substrate, the metal reflection film, or the like is likely to be damaged.